JP6130292B2 - Method for applying pattern to wrapping plate and wrapping plate - Google Patents

Description

BACKGROUND Hard disk drive systems (HDDs) typically include one or more data storage disks. A conversion head carried by a slider is used to read and write data tracks on the disk. The slider is carried by an arm assembly that includes an actuator arm and a suspension assembly, which may include a separate gimbal structure or may integrally form a gimbal.

  The density of data stored on the disk continues to increase, necessitating more precise conversion head positioning. Traditionally, in many systems, head positioning is accomplished by operating the actuator arm with a large scale actuating motor, such as a voice coil motor, to position the head over a bend at the end of the actuator arm. A high resolution head positioning mechanism, or microactuator, is advantageous to accommodate high data densities. The microactuator is often a piezoelectric microactuator.

  The electrical connection between the various elements in the HDD system should be strong, resistant to breakage and have sufficient conductivity. Improved electrical connections are always desirable. This disclosure provides an improved electrical connection to the slider and conversion head.

Overview One particular embodiment of this disclosure is a method of applying a pattern to a wrapping plate. The method includes providing a machining tool having a pattern including a plurality of raised teeth, each having a base, at least one sidewall, and a termination, and using the tool to pattern the wrapping plate. By providing, the process surface of the lapping plate is provided with the process surface which has the reverse pattern of the tool surface, and a pattern provision process deforms the process surface of a lapping plate plastically.

  Another particular embodiment of this disclosure is a patterned wrapping plate. The wrapping plate includes a work surface that includes a plurality of individual depressions separated by continuous land areas. Each recess has a depth of 100 μm or less from the processing surface to the end of the recess, and an inclined side wall extending from the processing surface to the end of the recess, and the maximum dimension of the recess on the processing surface is 1000 μm or less. is there.

  Another particular embodiment of this disclosure is a patterned wrapping plate. The wrapping plate is helical about the central axis of the wrapping plate and includes a working surface that includes grooves that form a plurality of turns and a land region that is positioned between adjacent turns of the spiral groove. . The groove has an inclined sidewall extending from the work surface to the end of the groove, a depth of 100 μm or less from the work surface to the end, and a varying width along the length of the groove.

  These as well as various other features and advantages will become apparent from a reading of the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS The disclosure will be more fully understood in view of the following detailed description of various embodiments of the disclosure in conjunction with the accompanying drawings.

2 is a partial side view of a magnetic recording disk drive and slider assembly. FIG. FIG. 2 is a top view of the magnetic recording disk drive and slider assembly of FIG. 1. It is a schematic side view of the Example of a wrapping plate and a slider bar. FIG. 6 is a schematic side view of an alternative embodiment of a wrapping plate and slider bar. FIG. 3 is a top plan view of a patterned wrapping plate constructed in accordance with an embodiment of this disclosure. FIG. 6 is an enlarged top plan view of a patterned wrapping plate constructed in accordance with an embodiment of this disclosure. FIG. 6 is a cross-sectional view of an example of a wrapping plate according to an example of the disclosure. FIG. 6 is a cross-sectional view of another embodiment of a wrapping plate according to an embodiment of this disclosure. FIG. 5 is a perspective view of a process for forming a wrapping plate according to an embodiment of the disclosure. FIG. 3 is a perspective view with an enlarged inset of a patterning tool used with an embodiment of this disclosure. FIG. 6 is a perspective view with an enlarged inset of another patterning tool used with an embodiment of this disclosure.

Detailed Description This example relates most generally to the manufacture of abrasive tools. For purposes of this description, but not limited to, refers to the use of an abrasive tool in high precision lapping of a slider and a supported magnetic transducer head used in a data storage device. Sliders and especially heads are operatively used to store and retrieve data on a rotatable magnetic recording disk and require very precise manufacturing tolerances. This disclosure provides a method of polishing (lapping) a slider with a lapping plate or table having a patterned working surface.

  The wrapping process uses either the slider bar's oscillating or rotating motion across the rotating wrapping plate to give a random motion of the slider bar on the wrapping plate, and the plate across the head surface during the wrapping process. Randomize the defects. Some lapping plates have a horizontal work surface without abrasives and are used in conjunction with a slurry of abrasive particles (eg diamond), while other lapping plates are machined with abrasive particles (eg diamond) horizontal Embedded in the surface. The general idea of interrupting the lapping surface, for example by forming grooves in the lapping plate, is known in the art. The patterned surface reduces the hydroplaning of the slider bar at the work surface, and liquid and residue (swarf) are removed centrifugally beyond the lap plate peripheral.

  There are problems with fluted plates, such as excessive groove width and / or depth, where abrasive particles loose their effectiveness due to lack of contact with the slider bar. Grooves that are too wide give surface discontinuities that are too severe for small workpieces. Even though the grooves can be properly sized, forming the grooves can be costly and time consuming. In addition, over time, the wrapping plate becomes worn and blunted, requiring a re-sharpening of the work surface, which can be more time consuming and costly, greatly reducing the total useful life of the wrapping plate. By forming a pattern on the wrapping plate as in this disclosure, improvements over conventional grooved plates are seen. Since the patterning process plastically deforms the wrapping plate surface rather than removing the material, the useful life of the wrapping plate is extended by allowing repeated sharpening of the patterned surface. The In addition, slider bars wrapped on a wrapping plate patterned by the disclosed method have reduced microscopic surface waviness compared to wrapping plates patterned by other methods.

  In the following description, reference is made to the accompanying drawings, which form a part hereof, and in which at least one specific embodiment is shown by way of example. The following description provides additional specific examples. It is understood that other embodiments are contemplated and may be made without departing from the scope or spirit of this disclosure. The following detailed description is therefore not to be taken in a limiting sense. While this disclosure is not so limited, an understanding of the various aspects of this disclosure can be gained through a discussion of the examples provided below.

  Unless otherwise indicated, all numbers representing the size, quantity and physical attributes of features are understood to be modified by the term “about”. Thus, unless indicated otherwise, the numerical parameters set forth are approximations that may vary depending on the desired attributes sought to be obtained by one of ordinary skill in the art using the teachings disclosed herein. .

  As used herein, the singular forms “a, an” and “the, the” refer to the plural unless the content clearly dictates otherwise. Examples having objects are included. As used in this specification and claims, the term “or” is generally used in its sense including “and / or” unless the content clearly dictates otherwise. It is done.

  With reference to FIGS. 1 and 2, a generic magnetic recording disk drive is shown having a magnetic recording disk 2 that is rotated by a drive motor 4 to which a hub 6 is attached. A read / write head or transducer 8 is present at the trailing edge or surface 9 of the slider 10. The slider 10 is connected to the actuator 12 by a rigid arm 14 and a suspension element 16. The suspension element 16 applies a biasing force that moves the slider 10 toward the surface of the disk 2. During operation of the disk drive, the drive motor 4 rotates the disk 2 in the direction of arrow 18 at a constant speed, and the actuator 12, typically a linear or rotary motion coil motor, moves the slider 10 generally radially. Driving across the surface of the disk 2, the read / write head 8 accesses different data tracks on the disk 2.

  In order to meet the increasing demand for more and more data storage capacity on disk 2, slider manufacturing and finishing must be improved to meet these demands. To meet these requirements, a lapping and polishing methodology that enhances slider characteristics must be developed. Typically, a large number of sliders are manufactured from a single wafer having a row of magnetic transducer heads provided simultaneously on the wafer surface using a semiconductor type process method. Single row bars are sliced from the wafer, each bar being a row of units that are further processed into sliders each having one or more magnetic transducers or heads on their end faces. Each bar is glued to a fixture or tool for further processing and then further dicing, i.e. separated into individual sliders.

  In order to achieve the maximum efficiency of the slider during use, the head, in particular the sensing element of the head, must have a precise dimension. During manufacture, it is very important that these elements be ground or lapped to very precise tolerances of the desired thickness to achieve the required intact functionality of the slider. This disclosure provides a wrapping plate that provides the required precision tolerance while maintaining a long plate life. The wrapping plate is formed by using a toothed patterning tool, and plastically deforms the surface of the wrapping plate to form a pattern on the processed surface.

  3A and 3B schematically illustrate a lapping plate (often referred to as a table) manufactured in accordance with this disclosure that is used for machining a slider bar. FIG. 3A shows the first embodiment as a wrapping plate 20A, and FIG. 3B shows the second embodiment as a wrapping plate 20B. Wrapping plates 20A and 20B have the same general general features, and unless specifically indicated otherwise, the discussion regarding one embodiment also applies to the other embodiment. The wrapping plates 20A, 20B have a body 22 with a processing surface or wrapping surface 24 on which the abrasive particles 30 are present. The body 22 has a plurality of depressions or cavities 25 therein, and a plurality of land areas 28 between the depressions 25. The recess 25 is formed by a toothed patterning tool, which tool and method are described below. The lapping plate 20A in FIG. 3A has the abrasive particles 30 on the land region 28, and the lapping plate 20B in FIG. 3B has the abrasive particles 30 in the recess 25.

  With reference to FIG. 3A, abrasive particles 30 may be present on land region 28. The abrasive particles 30 may be electroplated on the land area 28, applied adhesively, or physically pressed against the land area 28 and mechanically held. One method of physically pressing the abrasive particles 30 against the land area 28 is by applying an abrasive slurry to a work surface 24 made of a soft metal (eg, a tin alloy). Under pressure, the abrasive particles 30 are embedded in a soft metal. Alternatively, the abrasive particles 30 may reside in the depressions 25 as shown in FIG. In FIG. 3B, the abrasive particles 30 are held in the recess 25 via an adhesive (for example, epoxy resin) 32. Additional details regarding the use of adhesive in the recesses to hold abrasive particles can be found in US Patent Publication 2012/0009856, the entire disclosure of which is hereby incorporated by reference.

  In use, the wrapping plates 20A and 20B are rotated with respect to the slider bar 100 including a plurality of sliders 100A and 100B held in an engaged state that presses against the processing surface 24. The polishing action by the abrasive particles 30 on the work surface 24 removes material from the slider bar 100. Having areas without abrasive particles (ie, depressions 25 in FIG. 3A and land areas 28 in FIG. 3B) reduces slider hydroplaning on the wrapping plates 20A, 20B, and provides a microscopic surface on the slider bar 100. Reduce swell.

  4 and 5 show the working surface of a lapping plate having a plurality of individual individual depressions or cavities on the working surface. FIG. 4 shows a portion of a circular wrapping plate having an annular working surface, and FIG. 5 is an enlarged view of a portion of FIG. The work surface shown has a plurality of recesses 25 arranged in essentially parallel rows, identified in FIG. 5 as rows R1, R2, R3 and R4. Present between the recesses 25 is a land region 28. As in these figures, when the depressions 25 are individual and individual depressions, the land area 28 is a continuous surface interrupted by the depressions 25. In an alternative embodiment, land area 28 may comprise a plurality of unconnected areas.

  For understanding the orientation, as seen in FIG. 5, each row R1, R2, R3, R4 extends in the longitudinal direction (from top to bottom in the figure). The lateral or radial direction extends across the rows R1, R2, R3, R4 (from left to right in the figure).

  In some embodiments, rows R1, R2, R3, and R4 are concentric circles consisting of depressions 25 around the center point of the circular wrapping plate, so land area 28 is also concentric around the center point. . In another embodiment, the rows R1, R2, R3 and R4 are one continuous row consisting of indentations 25 that spiral out of, or spiral into, the central point of the circular wrapping plate. Thus, the land region 28 also spirals out of or enters its center point. In some embodiments, the depression 25 may be shaped and / or oriented such that the leading edge of the depression 25 is not radially aligned.

6A and 6B show two embodiments of the depression 25. FIG. In each figure, the depressions 25 in the working surface 24 are separated by land areas 28 having a length L. The recess 25 has a side wall 26 extending from the processing surface 24 to the bottom surface 29. The recess 25 has a maximum width or length dimension l ₁ measured at the work surface 24 and a smaller width or length dimension l ₂ measured at the bottom surface 29. Thus, the side walls 26 are beveled, angled or inclined side walls. In FIG. 6B, the depression 25 terminates at a point, and therefore the bottom surface 29 has a zero length dimension l ₂ . The depression 25 has a depth d as measured from the machining surface 24 to the bottom surface 29.

The shape of the recess 25 may be any suitable shape, but generally has sloped side walls 26 (ie, the dimension l ₁ measured on the work surface 24 is the dimension l _{2 on the} bottom surface 29. Bigger than). As seen in FIG. 5, when viewed from the top, the recess 25 may be circular, oval or elliptical, rectangular (including square), triangular, diamond, or any other polygonal shape. As seen in FIGS. 6A and 6B, when viewed from the side, the depressions may be pyramidal (as in FIG. 6B), or truncated or trapezoidal (as in FIG. 6A). Particularly suitable shapes for the recess 25 include truncated pyramid shapes (eg, truncated 3 side, truncated 4 side pyramid), elongated pyramid shapes, and frustoconical shapes (ie, truncated cones). A truncated or trapezoidal depression may be formed by a patterning tool having teeth with its truncated or trapezoidal shape, or may be formed by a patterning tool having pointed teeth, It is not completely pressed against the wrapping plate during the patterning process.

6A and 6B represent views from either direction of the dent rows, either longitudinally with the dent rows, or transverse (eg, taken radially) to the plurality of rows. In the case of a longitudinal view of a row, that shown in the figure is a cross-section of a portion of a row (the patterning tool is moved across the page to form each of the indicated depressions in sequence) In the case of multiple rows in a lateral or radial view, it is shown a cross-section of adjacent rows (each indentation is in a different row). The recess 25 may have the same dimensions l ₁ , l ₂ in the longitudinal direction and in the transverse direction or may be different. For example, the square depression 25 will have l ₁ and l _{2 the} same in the longitudinal and transverse directions. Rectangular recess 25, the _{l 1} and _{l 2} in the longitudinal direction, will have to be different from the _{l 1} and _{l 2} in the transverse direction. The indentations 25 may be equally spaced (ie, having the same length L therebetween) or vary in length as viewed in either the longitudinal or lateral or radial direction of the row. You may have length L in the meantime.

  The shape and size of the recess 25 varies depending on the wrapping process step in which the patterned wrapping plate is used. Most wrapping processes include three steps in the sequence: a coarse wrapping step, a fine wrapping step, and a kiss wrapping step. For the coarse lapping step, the abrasive particles (eg, diamond) are typically about 1 μm to about 5 μm in size; for the fine lapping step, the abrasive particles are typically about 0.1 μm to about 1 μm in size. For the kiss wrapping step, the abrasive particles are usually less than 0.1 μm.

In general, for any lapping step, the depth d from the work surface 24 to the bottom 29 is preferably 1000 μm or less, and in some embodiments about 500 μm or less. For the rough lapping step, the depth d from the work surface 24 to the bottom 29 is preferably 100 μm or less, in some embodiments about 10 μm or less, and in some embodiments about 5-10 μm. For a fine lapping step, the depth d from the work surface 24 to the bottom 29 is preferably 10 μm or less, and in some embodiments about 1 μm or less; For the lapping step, the depth d from the work surface 24 to the bottom 29 is preferably 1 μm or less, and in some embodiments about 0.5 μm or less. In general, for any lapping step, the maximum dimension of the recess 25 (for a tapered structure will be length l ₁ ) is preferably 100 μm or less, and in some embodiments about 500 μm or less. It is. For any of the lapping steps, a dimension l ₁ in the range of about 100 μm to about 200 μm is preferred.

As one specific example, for a tool having a pattern like that of FIG. 6A, the depression 25 has a largest dimension l _{1 at} the work surface 24 of about 790 μm and a dimension l at the distal end 29. ₂ is about 430 μm and the depth d is about 800 μm. As another specific example, for a tool having a pattern like that of FIG. 6B, the recess 25 has a largest dimension l _{1 on} the work surface 24 of about 700 μm and a distal end 29 is pointed. The depth d is about 800 μm.

  As discussed above, the wrapping plate of this disclosure is formed by forming a pattern on the wrapping plate with a toothed patterning tool. In some embodiments, the patterning process of this disclosure may be referred to as rolling or forming knurling; such a process may press the wheel or tool against the workpiece with sufficient force. This is done by cold forming or plastically deforming the outer surface of the workpiece. The patterning tool has an inversion of the pattern that is to be applied to the workpiece.

  FIG. 7 illustrates a preferred setting for providing a patterned wrapping plate. The support body 50 rotatably holds the toothed pattern application tool 52. As the support 50 moves radially across the rotating wrapping plate 20, sufficient pressure is applied by the support 50 to bring the tool 52 into contact with the plate 20, and reversing its pattern through a plurality of rows Rx, Apply to plate 20 with Ry or the like. If the support 50 moves continuously uninterrupted radially across the rotating wrapping plate 20, the result is one continuous spiral of depressions in the wrapping plate 20. Alternatively, the support 50 is fixed in place with respect to one rotation of the wrapping plate 20, after which the support 50 is lifted and another fixed position radially (in or out). The result is a concentric row of depressions in the wrapping plate 20.

  The rows of depressions can have equal or unequal spacing (in the radial direction) between them. For example, referring to FIG. 5, the radial distance between rows R1 and R2 is less than the radial distance between rows R2 and R3. Similarly, the radial distance between rows R3 and R4 is less than the radial distance between rows R2 and R3. FIG. 6B also shows a varying radial distance between rows when showing a side view consisting of multiple rows, and FIG. 6A shows an equal distance between rows.

  Two examples of suitable patterning tools are shown in FIGS. FIG. 8 shows the first embodiment as a pattern application tool 52A, and FIG. 9 shows the second embodiment as a pattern application tool 52B. The patterning tools 52A, 52B have the same overall general characteristics, and unless specifically indicated otherwise, the discussion regarding one embodiment also applies to the other embodiment. Each tool 52A, 52B has a plurality of teeth 54 extending around the outer periphery 55 of the cylindrical tools 52A, 52B. Each tooth 54 has at least one side wall 56 that extends from the outer periphery 55 to the distal end 59. The cross-sectional area of the tooth 54 (taken essentially parallel to the outer periphery 55) tapers from the outer periphery 55 to the distal end 59. For the tool 52A of FIG. 8, the adjacent side walls 56 (ie, those of adjacent teeth 54 facing each other in the circumferential direction) are inclined away from each other, and the outer side walls 56 (ie, circumferentially orthogonal to the side walls 56). Is not inclined, but extends orthogonally from the outer periphery 55. Conversely, for the tool 52B of FIG. 9, all four sidewalls 56 are angled or inclined toward the distal end 59. All sidewalls 56 may have the same angle from the perimeter 55 to the distal end 59 or may have different angles. In both the patterning tools 52A and 52B, the distal end 59 is a flat polygon—a rectangle for the tool 52A and a square for the tool 52B—and is pointed like the recess 25 in FIG. 6B. The tool used to form the pointed depression has a line point that defines the distal end 59.

  In order to form a patterned wrapping plate in accordance with this disclosure, a patterning tool 52A, 52B or others is mounted on a support 50 as shown in FIG. As the support 50 moves radially across the rotating wrapping plate 20, sufficient pressure is applied by the support 50, and the rotating patterning tool deforms the surface of the wrapping plate 20 to cause the pattern to move. Inversion is applied on the plate 20 in a plurality of rows Rx, Ry, etc. In some embodiments, sufficient pressure may be applied to the patterning tool to cause the entire tooth 54 to fit into the plate surface, causing the surface to deform and form a depression, but in most embodiments, Only a portion of the teeth 54 will fit into the plate surface.

  Many variations of the patterning tool and the method using the patterning tool can be formed to form a patterned wrapping plate while maintaining the overall inventive design and staying within the scope of the disclosure. It is understood. A number of alternative designs or element features have been mentioned above.

  Thus, a method of applying a pattern to a wrapping plate and an example of a patterned wrapping plate is disclosed. The implementations described above and other implementations are within the scope of the following claims. Those skilled in the art will appreciate that the invention may be practiced with embodiments other than those disclosed. The disclosed embodiments are presented for purposes of illustration and not limitation, and the invention is limited only by the claims.

  20 wrapping plates, 24 machining surfaces, 52 machining tools, 54 teeth, 56 side walls, 59 distal end.

Claims (4)

A method of applying a pattern to a wrapping plate,
Providing a machining tool having a pattern including a plurality of raised teeth, each raised tooth having a base, at least one sidewall, and a terminal end, and the method further comprises:
Applying a pattern to the wrapping plate using the tool to provide a processed surface having a reversed pattern of the tool surface on the processed surface of the wrapping plate, the working surface is plastically deformed, wherein the machining tool is seen including wheel involves a central axis, and a plurality of raised teeth on the outer periphery of said wheel, said end portions of the plurality of raised teeth flat A method for defining a surface .   The method of claim 1, wherein applying the pattern comprises rotating the processing tool about the central axis. A lapping plate containing working surface comprising a continuous multi separated by land areas separate rectangular recess, before Symbol depression,
A depth of 1 μm or less from the processing surface to the end of the recess, and an inclined side wall extending from the processing surface to the end of the recess,
The wrapping plate, wherein the maximum dimension of the recess on the processed surface is 1000 μm or less. A wrapping plate including a processed surface, wherein the processed surface is
It helically around the central axis of the front Symbol lapping plate comprises grooves forming a plurality of旋曲the interval in the radial direction is varied, the groove,
An inclined sidewall extending from the work surface to the end of the groove;
A depth of 1 μm or less from the processed surface to the end portion;
Having a varying width along the length of the groove, the work surface further comprising:
A wrapping plate including a land region positioned between adjacent turns of the spiral groove.